Apparatus for packaging



Aug. 20, 1968 G. E. ALLEN, JR, ET AL 3,397,506

APPARATUS FOR PACKAG ING 5 Sheets-Sheet 2 Filed Oct. 21 1965 L/MAM,M

ATTO RNEYJ Aug. 20, 1968 G N, JR ET AL 3,397,506

APPARATUS FOR PACKAGING Filed Oct. 21, 1965 5 sheets sheet 3 INVENTORS I3. Gee/v7- Z /94/V, 12.

GAE/Y 7 Faamasamde. Y fi/c/mw fi fly/v0 ZW, Mug, 7:34AM

ATTORNEYS Aug. 20, 1968 Filed Oct. 21. 1965 G. E. ALLEN, JR.

ET AL APPARATUS FOR PACKAG ING SSheets-Sheet 4 G'Rmvr Z. 445, dd.

.4 1v Rea/050M, .Ae Flax/map B.//Y/m9/v ATTORNEYS Aug. 20, 1968 ,G. E.ALLEN, JR, ET AL APPARATUS FOR PACKAG ING 5 Sheets-Sheet 5 Filed Oct.21, 1965 INVENTORS 6 am),- Zf'flzz E/V, JR. 6'45 7 Fae/Asa BYF/c A69!.5. [IV/V194 M 9' M v ATTORNEYS United States Patent ABSTRACT OF THEDISCLOSURE Apparatus for flushing a package with a gas other than airand closing the package. The apparatus is adapted for use with a cup,preferably semi-rigid plastic, having walls and a bottom with a flangeextending outwardly from the top of the walls. A lid rests on the flangeat opposite sides of the package and is bowed upwardly over the centerof the package to provide a kind of tunnel for air and gas flow. Theapparatus includes a suction inlet and an outlet for the replacementgas, positioned adjacent opposite sides of the package. The package ismoved between these and gas flows through the aforesaid tunnel. Then thepackage moves to another station where the lid is sealed against theflange.

The present invention relates to packaging and more particularly to anapparatus and a method for the packaging in containers, such as rigid,transparent or translucent plastic, of products including slicedluncheon meat and other perishable goods. The invention embraces a novelapparatus which is an improvement of the apparatus described in the U.S.patent application of Richard Inman, Ser. No. 398,721 filed Sept. 23,1964, and includes a conveyor, means for replacing air in the packageswith another gas and means for sealing it while the package is advancedby the conveyor.

As explained in the Inman application, there has been a need for aninexpensive package for sliced luncheon meat and the like which has arigid transparent plastic compartment or cup and a lid to hermeticallyseal the opening of the cup. Such a package is described in the US.patent application of Harmon B. Miller, Ser. No. 384,846, filed July 24,1964. The aforesaid Inman application describes apparatus and a methodfor replacing air in the package with another gas such as an inert gasand closing the package with a hermetically sealed bid. Typically, thegas may be carbon dioxide. In that apparatus the package, having anunsealed lid over it, is moved by a conveyor from a vacuum chamber, pasta membrane, to a chamber containing another gas, and the gas thereby isswept through the package as it passes the membrane.

It has been found in practice that the speed of operating that apparatusis limited by the need for relatively high efiiciency of gas flushing.That is, in a preferred form of that apparatus, a package is movedstep-wise from a filling station, to the vacuum chamber and then to thegas chamber. As the speed of the apparatus is increased, the time duringwhich gas is swept through the package is decreased; therefore the speedof the apparatus is limited.

In accordance with the present invention, gas is swept through thepackage while it is stationary in a chamber. The conveyor convenientlywill be stationary for a reasonably long interval while completedpackages are ejected and unclosed packages are inserted and thisprovides suffieient time for flushing the package without restrictingits speed when the packages are in motion. Therefore, theabove-described delay is not experienced it the flushing is carried outthen.

The flushing operation is accomplished by bowing the lid upwardly overthe package to form a kind of tunnel and providing a pressuredifferential between the ends of the package. In the preferred form ofthe apparatus, the package is carried within a moving table, and gas andvacuum are provided by tubes which open downwardly toward the tableadjacent the ends of the package.

The apparatus and its mode of operation will be better understood fromthe following detailed description of a preferred embodiment thereof,and by reference to the drawings, in which:

FIG. 1 is a perspective view of the apparatus;

FIG. 2 is a perspective view of the portion of the apparatus in whichgas flushing takes place;

FIG. 3 is a side elevation, partially in section, of the apparatus ofFIG. 1, with some parts removed for simplicity;

FIG. 4 is a rear elevation of the lower portion of the apparatus;

FIG. 5 is an elevation, partly in section, of the lower portion of theother side of the apparatus; and

FIG. 6 is a plan view of the apparatus.

For convenience of description, the apparatus may be considered to besubdivided into a rotating table 1 which carries the packages, aflushing chamber 2, a label dispenser 3, a package closing chamber 4, aheat sealing press 5, and the drive mechanisms indicated generally at 6which are beneath the rotating table 1.

The table 1 is a closed end hollow cylinder mounted for rotation about avertical axis. There are six openings 7 in the top of the table toreceive packages and there is a basket 8 under each of the openings toprovide a relatively air-tight cavity around the packages. There is anopening 9 in the bottom of each basket and a piston 10 is slidablymounted therein for vertical movement. The top 11 of the piston isrelatively wide and ejects a package when the piston is raised by a camunder the table.

At the edge of each opening 7, there is a recessed ledge 12, whichreceives a mandrel 13. The mandrel has a central opening 14, the edge ofwhich is recessed to provide a ledge 15, the shape of which is shownbest in FIG. 2. The dimensions of the ledge are slightly larger thanthose of the cup which is to be inserted in it. Several mandrels may besupplied with the apparatus, having central openings which acceptvarious sizes and shapes of packages, thereby permitting easy conversionfrom one packaging operation to another.

The gas flushing chamber 2, best seen in FIG. 2 is preferablyconstructed of transparent plastic, permitting observation of theflushing step. It comprises sides 16 and a top 17. A gasket is providedunder the sides which makes a relatively gas-tight seal with the top ofthe rotating table 1.

At the radially inner and outer ends of the top, there are threadedopenings in which are inserted elbow tubing connectors 18 and 19. Theseare attached to tubes 20 and 21 which lead to vacuum and gas sources.

The label dispenser 3 is at one side of the rotating table 1 andincludes .a hopper 22 mounted directly over the path of the packages.The hopper is slightly more narrow than the labels so that they aremaintained in a slightly bowed condition. Interchangeable hoppers may besupplied with the apparatus to permit easy adaptation to several sizesof packages.

Labels are dispensed by a moving arm 23 which extends radially inwardlyover the table. The arm 23 carries two rubber suction cups 24 and 24'and means are provided for alternately supplying vacuum and air underpressure through a tube in the arm to openings within the suction cups.In operation, the arm is raised with the suction cups turned upwardly,until they touch the bottom of the labels in the hopper 22. Suction isapplied and the arm is lowered, withdrawing the bottom label. The arm isrotated 180 as it moves downwardly to invert the label, and places thelabel on a package in a mandrel 13 at the bottom of its stroke. At thatpoint, the arm actuates a microswitch (not shown) which operates a valvedisconmeeting the suction and introducing air under pressure to thesuction cups. This causes the labels to drop quickly onto a package.

The package closing chamber 4 is spaced 60 from the gas flushing chamberand comprises sides 25 and a top 26 suspended from a crank housing 27and resting on the rotating table 1. A gasket 28 is under the sides toprovide a relatively gas-tight seal to the rotating table 1. Theradially inward side is removable, being held in place by quick detachdevices, permitting access to a heat sealing mechanism and removal of apackage in case of malfunction.

Between the gas flushing chamber 2 and the package closing chamber 4there is a low chamber 4'. This is a casting having a top and sides, thesides resting on a gasket, which makes a relatively gas-tight seal withthe table. The chamber 4 is attached at one end to the package closingchamber 4 and at the other end carries clips which hold the sides 16 ofthe gas flushing chamber against it. It prevents unnecessary escape ofthe gas as the package is moved from the gas flushing chamber to thepackage closing chamber.

The package is closed by the heat sealing press which includes anelectrical heater 29 and an easily interchangeable heating platen 30depending from and in contact with the heater. The platen includes adownwardly extending member having the shape of the outer edges of thepack age to apply heat and pressure to the edge portion only of the lid,thereby heat sealing the lid to the package without excessive heating ofits contents. The electrical heater is at the bottom of a plunger 31which is mounted for vertical sliding movement in a compartment 32 atthe inner end of the crank housing 27. The plunger carries alaterally-extending pin 33 on which is mounted a ball bearing whichengages in a slot in the inner end of the bell crank 34, the bell crankbeing pivotally mounted in the outer end of the crank housing. Verticalmovement of the plunger is accomplished by inward and outward movementof the lower extremity of the bell crank, by means to be describedfurther herein.

As a package leaves the package closing chamber 4, it indexes to thenext station where it is raised by the piston and ejected. A piston ismaintained elevated at the ejection station and then an arm 35 sweepsacross, propelling the package outwardly onto a downwardly inclinedconveyor 36. The piston is lowered as the table indexes to its nextposition.

The drive mechanisms are in a housing beneath the table 1. All power forthe above-described mechanical movements is provided by an electricmotor 37. A clutchbrake mechanism 38 is connected to the shaft of themotor which alternately supplies motion to and brakes the moving parts.That is, when motion is to be supplied, the clutch, which is connectedto the motor shaft, is engaged and the brake, which is connected to anoutput drive shaft 39, seen in FIG. 4, is disengaged. To stop motion,the clutch is disengaged, and, substantially simultaneously, the brakeis engaged.

A pulley 40 is mounted on the output drive shaft 39, connected by a beltto another pulley 41 on an input shaft 42 of a reduction gear set 43.The output of the reduction gear set is an upwardly-extending verticalshaft 44 on which are mounted a sprocket wheel 45 and a cam 46.

The cam 46 operates the bell crank 34, by means of a horizontal crankarm 47 to reciprocate the heating platen 30. One end of the crank arm ispivotally mounted on the housing of the drive mechanism 6, and the otherend is pivotally mounted on a link 48 which in turn is pivotallyconnected to the bottom of the bell crank 34. At the center of the crankarm, there is a depending bearing 49 which engages the cam 46, and, tohold the bearing against the cam, there is a tension spring attached, atone end, to the link 48 and, at the other end, to the housing. The,construction of the cam is such that spring tension holds the heaterelevated during most of the cycle of the apparatus. The heating platenis depressed briefly onto a package while the table is stationary.

The sprocket wheel 45 is connected via a chain 50 and a sprocket wheel51 to the input shaft of a Geneva drive mechanism 52. The intermittentoutput of the Geneva drive is through a vertical shaft 53 on which thetable is mounted.

The package ejector mechanism comprises a vertically reciprocating rod54 pivotally connected at its bottom to one end of a cam actuated crankarm 55, the middle of which is pivotally mounted on the housing. Thereis a cam 56 on the input shaft of the Geneva drive which engages abearing 57 on the crank arm 55. The cam raises and lowers the rod 54which is normally held down by a spring 58, the bearing 57 consequentlybeing urged upwardly against cam 56. During approximately 270 degrees ofrotation of the input shaft of the Geneva drive and cam 56 while table 1is stationary, cam 56 elevates rod 54 and theerfore piston 10. Thisconstruction causes the package to be elevated for removal by the arm35.

The sweep arm 35 is secured at the top of a vertical shaft 60 mountedfor rotation in a bearing in the housing. At the lower end of the shaft60, there is attached one end of a connecting rod 61. The other end ofthe connecting rod carries a pin 62 and also is connected to a tensionspring 63. The other end of the tension spring is attached to thehousing and it pulls the connecting rod 61 to turn the shaft 60 andhence the sweep arm 35 to its retracted position.

There is a sprocket wheel 64, mounted to engage the chain 50, to whichthere is pivotally attached one end of a crank arm 65. At the other endof the crank arm 65, there is an elongated slot which receives the pin62. As the sprocket wheel 64 turns, the crank arm 65 moves theconnecting rod 61 against the tension of spring 63 and then provideslost motion as the sprocket wheel continues to turn. Consequently, thearm 35 sweeps a package from the table, retracts, and then remainsstationary as the cycle of operation continues.

Electrical control of the moving parts of the apparatus is achieved by amicroswitch actuated relay which operates the clutch-brake 38. Themicroswitch 66 is at the end of a conduit 67 pivotally mounted to theside of the package closing chamber 4. Normally, the switch ispositioned adjacent to the package insertion station. The person whoinserts packages closes the switch momentarily by pushing a long rod 68to one side. This causes the clutch-brake 38 to operate and initiates apackaging cycle. In this cycle, a lid 'is placed on a package, gas isflushed through another package in chamber 2, a lid is heat sealed to athird package in chamber 4 and a fourth package is ejected. When all ofthe operations in a cycle are completed, the clutch-brake is reversedelectrically by a mechanically-operated microswitch (not shown).

An important feature of the present invention is the opening into themandrel 13, which is only slightly wider than the cup to assure properalignment with the lid dispenser and heating platen. It may also help inkeeping the lid bowed if the lid is a little wider than the cup and theopening into the mandrel so that the lid must be bowed in order to fitwithin the mandrel. However, a lid of aluminum foil or aluminum foillaminated to paper, which is preferred for its high efiiciency as a gasbarrier, will remain bowed witout this construction. It also is possibleto use a cardboard lid which is scored to fold into a bowed shape. Theseprovide a further advantage in that, when the package is closed, the lidremains slightly elevated at its center for an attractive appearance.

The ledge 15 is recessed below the top of the table to provide spaceabove the cup into which the lid is bowed. As a result, a tunnel isformed over the cup by the lid, but the bowed lid can still pass underthe gasket which seals the chamber 2 to the rotating table 1. Gas flowsthrough this tunnel and around the contents of the package, sweeping airbefore it to a vacuum at the other end.

A strong vacuum is not required, because removal of air is accomplishedprincipally by a sweeping action. In practice, air is exhausted fromchamber 2 through hose 21 by a positive displacement vacuum pump (notshown) at a rate of 80 cubic feet per hour. Another gas such as an inertgas from an external source is inserted into chamber 2 by hose 20' andfitting 18 at a rate of 100 cubic feet per hour. During a one-seconddwell time, a typical package will be flushed approximately three timesremoving 85% of the original air and replacing it 'with another gas. Theexcess gas inserted into chamber is used to maintain a positive pressurein the flush chamber 2 and in heat seal chamber 4 thereby keeping airfrom leaking in under gasket 28. It is possible to omit the vacuumentirely, by using higher pressure of the other gas, but this is lessdesirable since there are greater gas losses and consequently highercosts.

Flushing efiiciency is increased and gas losses are minimized by thesmall size of the gas flushing chamber 2. The top of the chamber may beflush against the table so that the chamber is in efiect only within therecess in the mandrel 13.

The gas inlet and vacuum outlets are provided by holes in the top of thechamber 2 which open downwardly near the ends of the package. In thepreferred embodiment, these holes are beyond the path in which thepackage moves, although they may overlap the ends of the packageslightly. Since the top of the chamber is close to the lid, it is notnecessary to continue the inlet and the outlet into the chamber, i.e. toextend the elbow tubing connectors 18 and 19 below the top 17 of thechamber. However, if the top of the chamber is relatively high above thepackage, it may be desirable for them to extend into the chamber or tohave the tubes open laterally toward the ends of the package.

In the preferred embodiment shown in the drawings, gas flow isfacilitated by extensions 66 and 67 of the ledge under the openings inthe top of chamber 2. That is, the ledge 15 is only slightly larger thanthe package, at the sides, for package alignment, but is enlarged toform semicircular pockets, directly under the gas and vacuum inlets,having, for example, the same depth as the ledge 15. Gas flowing intoone of these pockets is directed toward the package by the sides of thepocket, and similarly air flowing into one of the pockets from thepackage is urged upwardly to the vacuum tube.

The apparatus and method are useful for replacing air with any othergas. Ordinarily, the other gas will be an inert gas, since spoilage ofproducts such as sliced luncheon meat is accelerated by oxygen in air.Carbon dioxide is a very suitable inert gas. However, it has beenproposed that oxygen is desirable for preserving the freshness ofcertain products such as fresh meats and vegetables. It will beappreciated that the apparatus and method described above are just asuseful for replacing air with oxygen-containing gases or any other gasesas they are for flushing with inert gases.

Various modification of the structure of the apparatus and mode ofoperation are possible, without departing from the scope of theinvention. For example, a package conveyor may be used which carries thepackages in a straight path. Closing means other than heat sealing meansmay be substituted. Automatic package inserting equipment may be added;in that case the microswitch actuated relay control and clutch-brakemight be omitted or the microswitch replaced with a device which detectsthe insertion of a package. The package may be made of other materialsthan plastic, for example, metal foil. Therefore, while preferredembodiments have been described and illustrated in the drawings, nolimitation thereto is intended, the scope of the invention being definedby the appended claims.

We claim:

1. Apparatus for replacing air with another gas in a package whichcomprises a cup and a bowed lid over said cup forming a tunnel throughwhich inert gas flows,

said apparatus comprising a conveyor for said package, means connectedto a source of said other gas under pressure for discharging said othergas adjacent one side of said package, means for withdrawing airadjacent another side of said package, and means for moving saidconveyor with said package along a path substantially perpendicular tothe line connecting said gas discharging and air withdrawing means whilesaid gas discharging and air withdrawing means are substantiallystationary along said path, thereby providing relative movement betweensaid package and said line so that said sides of said package move pastthe gas discharging and air withdrawing means at substantially the sametime and gas flows through said package.

2. Apparatus as set forth in claim 1 in which said conveyor comprises atable having an opening to receive said cup and a recessed ledge at theedge of the opening in said table, whereby said cup may rest on saidledge and space is provided for said bowed lid above said cup but withinsaid table, said gas discharge means and said air withdrawing meanscomprising conduits opening toward said ledge and said ledge beingenlarged adjacent said conduits to form pockets, the sides of whichdeflect said other gas toward said package and air toward said airwithdrawing means.

3. Apparatus as set forth in claim 1 including a gas flushing chamberhaving a side opening against said table and forming a relativelygas-tight seal therewith, said bowed lid passing under a wall of saidflas flushing chamber as said table moves, and said gas discharge meansand air withdrawing means opening into said chamber.

4. Apparatus as set forth in claim 1 in which said means for moving saidconveyor includes means for stopping the conveyor when a package isadjacent said gas discharge means and air Withdrawing means.

5. Apparatus as set forth in claim 1 including means for hermeticallysealing said lid to said cup.

6. Apparatus as set forth in claim 5 including means for removing asealed package from said conveyor.

7. Apparatus as set forth in claim 2 in which said conveyor is arotating table and said means for moving said conveyor comprises meansfor rotating said table.

8. Apparatus as set forth in claim 3 in which said ledge is enlargedadjacent said gas discharge means to form pockets, the sides of whichdeflect said other gas towards said package and air toward said airwithdrawing means.

9. In an apparatus for flushing an at least partially open containerwith gas comprising:

a plurality of wall members defining a partially enclosed gas flushingchamber,

a conveyor in sliding engagement with at least some of said walls tosubstantially close said chamber and for moving said container intocommunication with the interior of said chamber to be flushed with gas,said conveyor comprising a moving wall of said chamber,

said conveyor having an opening receiving said container and an elevatedlid on said package, and means for supporting said container and lidwithin said opening and below the surface of said conveyor,

means connected to a source of said gas for discharging said other gasadjacent one side of said container, means for withdrawing air adjacentanother side of said package,

and means for moving said conveyor slidably past said plurality of wallmembers,

whereby said container may be placed in said conveyor 7 v 8 outside saidchamber with a lid resting on it and gas discharging and air withdrawingmeans permitpartially elevated to permit access of gas into said tingincreased gas flow time. container and whereby sa'id container with saidelevated lid may be moved into said chamber past References Cited thewall members which slidably engage said conveyor without substantial gasleakage from said UNITED STATES PATENTS chamber to the atmosphere;3,189,505 6/1965 Sloan et a]. 53-22 X the improvement in which saidmeans for moving said 3,196,590 7/ 1965 Ollier et a1. 53112 conveyormoves the packages along a path substantially perpendicular to the lineconnecting said 10 TRAVIS S. MCGEHEE, Primary Examiner.

